Differentiated services (DiffServ) is a computer network protocol that specifies a scalable and coarse-grained mechanism for classifying and managing network traffic to provide quality of service (QoS) on modern Internet protocol (IP) networks. DiffServ operates on the principle of traffic classification, whereby each data packet is classified into a particular traffic class. Each traffic class may be managed differently from a QoS perspective to ensure preferential treatment for higher-priority traffic on the network, such as providing low-latency capability to critical network traffic, such as voice or streaming media, while providing simple best-effort service to non-critical services, such as web traffic or file transfers. DiffServ classifies packets and policing at the “edges” of the network and uses a 6-bit differentiated services code point (DSCP) for packet classification in an 8-bit differentiated services field (DS field) in the IP header.
Computer networking has gravitated to cloud computing as a preferred computing environment due to its versatility over traditional computer networks. One aspect of a cloud-computing environment's versatility is its ability to support multiple tenants. To support multiple tenants, cloud-computing environments may employ network virtualization, which provides each tenant its own address space that may overlap other tenants' address spaces. Network virtualization involves packet encapsulation, and Network virtualization over layer 3 (NVO3) is becoming one of the preferred packet encapsulation approaches. NVO3 provides a tunnel technology that encapsulates layer 2 packets to the layer 3 layer and adds an overlay header to extend and divide needed address spaces.